The present invention relates to a heating and/or air-conditioning system for a vehicle interior including a central air-conditioning device, an air-conveying device, or an air-conditioning and air-conveying device for at least one of regulating the temperature of, cooling, drying, humidifying, cleaning, and conveying air, and a plurality of air inlet and air outlet openings distributed in the vehicle interior.
In order to obtain a pleasant climate for the occupants of a vehicle, it is endeavoured to provide temperature layering in the vehicle interior. This is based on the principle of “warm feet, cool head”, i.e. the aim is to achieve a warm footwell and a cooler head and upper body.
Air-conditioning systems therefore often have separate air ducts for the foot region and the head region, the air ducts of the foot region being charged with warmer air than those of the head region.
In order to reduce the energy use which is required for conditioning the air, the vehicle interior is not only fed with pure fresh air, but part of the already pre-conditioned air from the vehicle interior is also used. Since this air in the interior has, for example in heating operation in winter, a higher temperature than the outside air, the energy use required for heating purposes is therefore reduced. However, the air in the interior is, as a rule, very humid and can therefore only be re-used to a limited extent, since otherwise the windows could become misted from the inside.
German publication DE 198 01 979 A1 discloses a vehicle air-conditioning system which has outside-air intake openings and inside-air intake openings. The air-conditioning housing has a separating plate which separates the air-conditioning housing into two air passages, so that the outside air is guided through one part of the air-conditioning housing and the inside air is guided through the other part. In order to prevent the windows from becoming misted, the outside air is then blown in the direction of the windscreen and the inside air in the direction of the foot region. However, the air which is blown in becomes thoroughly mixed in the interior quite rapidly, so that, in order to avoid a misting tendency, ventilation has to be carried out using a high proportion of outside air. The energetic advantage obtained is therefore relatively low, especially in view of the construction which is still very complicated and therefore also quite expensive. In addition, the inside air has first of all to be conveyed from the vehicle interior to the air-conditioning housing, conveyed through the latter and subsequently conveyed back into the vehicle interior, which has the consequence of very high flow losses which, in turn, have to be compensated for via a powerful fan.
One object of the invention is the object of providing a heating and/or air-conditioning system for a vehicle interior, which system is constructed simply in terms of structure and makes good heating and/or cooling of the vehicle interior possible with as little energy use as possible. The heating and/or air-conditioning system is preferably to be designed in such a manner that it prevents, with a proportion of outside air which is as small as possible, the windows from becoming misted from the inside.
This object is achieved according to the invention by a heating and/or air-conditioning system in which the air inlet openings and the air outlet openings are assigned to one another so that the air fed into the vehicle interior through one of the air inlet openings is for the most part removed through an assigned air outlet opening.
A plurality of air inlet openings and a plurality of air outlet openings are provided in the vehicle interior. In this case, the direction of the air inlet refers to the vehicle interior, so that the air inlet opening ventilates the vehicle interior and the air outlet opening evacuates the vehicle interior. The air inlet openings and the air outlet openings are arranged in such a manner that an air inlet opening or a number of air inlet openings interact with an air outlet opening or a number of air outlet openings, so that predetermined air flows are formed in the vehicle interior. An air inlet opening or a number of air inlet openings is/are assigned to an air outlet opening or a number of air outlet openings. In particular, the exact amount of air fed into the vehicle interior through an air inlet opening or a number of air inlet openings is removed again through the assigned air outlet opening or the assigned air outlet openings. It is therefore possible to feed differently conditioned air, for example differently temperature-regulated air or differently humid air, at the same time next to one another into the vehicle interior and to remove this air again and, in the process, largely to avoid an undesirable mixing of the differently conditioned air.
The air inlet and air outlet openings are preferably designed and/or arranged in such a manner that the air fed through an air inlet opening flows along a closed flow path to the assigned air outlet opening or the assigned air outlet openings. The formation of the closed flow paths in the vehicle interior is essential in order also to obtain a separation of differently conditioned air inside the vehicle.
Provision is made for the central air-conditioning and/or air-conveying device, i.e. the device arranged at a central point in the vehicle, for example in the engine compartment or in the cockpit region, to convey outside air and to condition it in accordance with the desired interior climate in a manner which can be set in advance. This means, for example, that in winter cold outside air has to be greatly heated up or in summer hot outside air has to be greatly cooled, for which purpose a correspondingly high expenditure of energy is required in each case. The central air-conditioning and/or air-conveying device may comprise a fan and/or a heat exchanger and/or an evaporator for preparing and/or conveying the air.
In order now to provide a pleasant interior climate in the vehicle with a low expenditure of energy, interior air which has already been pre-conditioned is therefore advantageously used for air-conditioning purposes; this is referred to as a circulating-air operation. However, this circulating air has the disadvantage that it is humid. This interior air can therefore only be used in the region of the footwell, since otherwise an impairment of the comfort of the occupant occurs or even, as a consequence of the humid circulating air, the windows could become misted from the inside.
One concept of the present invention therefore envisages separating the flow paths not only for the conditioning and/or conveying of the air, but also in the interior of the vehicle. The misting tendency is therefore reduced and the required expenditure of energy, preferably for heating purposes, is reduced. In particular, the proportion of outside air which is additionally to be conditioned with high energy use is reduced by reducing a thorough mixing of the air in the interior.
In order to obtain a particularly good separation of the flow paths, use is preferably made of surfaces which are present in the vehicle interior as guiding surfaces for the flow. Thus, for example, one flow can be guided along the windows and the roof lining and/or one flow can be guided along the floor and a seat surface in a footwell.
One design of the invention envisages the air inlet openings and the air outlet openings having a rectangular air inlet surface or air outlet surface with a narrow transverse extent and long longitudinal extent. As a result, in a first approach, the air is dispensed into the inside of the vehicle and also removed again linearly, so that a virtually two-dimensional flow is produced which is guided, for example, along the windows and the roof The two-dimensional flow may also become closed, by appropriate air conveying and/or arrangement of the air inlet and air outlet surfaces, to form a three-dimensional flow configuration, for example a roller, in order readily to aerate the footwell, in particular.
One advantageous design of the invention envisages forming individual air inlet openings as outside-air inlet openings and the associated air outlet openings as outside-air outlet openings. Accordingly, it is also envisaged to form individual air inlet openings as circulating-air inlet openings and the associated air outlet openings as circulating-air outlet openings. Air inlet openings and air outlet openings which can be switched between outside-air and circulating air may also be provided.
The heating and/or air-conditioning system may, in particular, have a plurality of operating modes, and thus, for example, a pure circulating-air operation may be provided, in which more circulating-air outlet openings are required, or a pure outside-air operation may be provided, in which more outside-air outlet openings are required, in which case individual air inlet openings and air outlet openings can be correspondingly switched. A mixed operation having variable, preferably preselectable proportions of outside air to circulating air is also provided.
In an advantageous manner, openings guiding the outside air can be arranged in the head or chest region of the vehicle interior, and openings guiding the circulating air can be arranged in the footwell, for example in the driver's footwell and/or front passenger's footwell and/or rear footwell. A layering of the air in the vehicle interior is thus obtained, in which case fresh and/or dry and/or conditioned outside air is arranged at the top in the head/chest region of the vehicle interior and circulating air is arranged in the footwell or the footwells.
One advantageous design of the invention envisages the circulating air being circulated in the footwell in a roller-shaped or cylindrical manner. The roller-shaped or cylindrical circulation of the circulating air produces an inherently closed and stable flow configuration in the footwell, so that an undesirable thorough mixing of the circulating air with outside air is greatly suppressed.
In one design, it is envisaged, for the roller-shaped circulation, to arrange in the footwell a unit for conditioning and/or conveying circulating air, which unit comprises a circulating-air inlet opening and an associated circulating-air outlet opening. A unit of this type is preferably arranged in each footwell, so that one unit for conditioning and/or conveying circulating air is present per vehicle occupant. The circulating-air outlet opening of the unit can be connected to the circulating-air inlet opening via a local air-recycling duct, i.e. a duct which is arranged locally in the vehicle interior, the duct being formed separately and in a spatially separate manner from the central air-conveying and/or air-conditioning device. The circulating-air outlet opening and the circulating-air inlet opening can be arranged closely adjacent, so that the air-recycling duct can be relatively short and, consequently, also only has a small flow resistance. Furthermore, components for conditioning the circulating air, for example a heat exchanger and/or electrical heating system and/or a Peltier element and/or air filter and/or devices for air drying and/or air humidifying can be arranged in the air-recycling duct. The circulating air therefore remains locally in the region of the footwell and is conditioned with very low flow resistances at a local point. Long and structurally complicated air ducts which, in addition, are very much afflicted by losses are therefore avoided.
In order to convey the air, provision is furthermore made for a local air-conveying unit to be arranged in the local air-recycling duct of the unit. The air-conveying unit is advantageously designed as a disc fan. The disc fan has a rotating assembly of a plurality of parallel discs of small thickness, two discs in each case bounding an air gap situated in between. The disc fan is designed in such a manner that its intake direction and its blow-off direction are situated in one plane. Owing to this characteristic construction, the disc fan requires, in particular, the formation of stable and inherently closed flow rollers. It is likewise of advantage that the disc fan has, owing to its manner of construction, only a very low noise level, so that complicated noise-damping measures, which are associated with flow losses, can be reduced or entirely omitted.
It is also envisaged to design the fan as an axial fan, in particular as a roller-type fan.
In one design of the invention, it is envisaged that the units which are arranged locally in the footwell and are intended for conditioning and/or conveying circulating air can be controlled and/or regulated independently, so that a passenger can set an individual climate in his region. Furthermore, it is also envisaged that the units can be controlled as a function of the central air-conveying and air-conditioning device, so that central heating and/or climate settings are possible.
Designs are also possible which provide, in addition to circulating-air operation, pure outside-air operation for rapidly changing the interior climate, for example drying and/or cooling and/or heating it, or a mixed operation of outside air and/or circulating air. In particular, individual air inlet openings and/or air outlet openings are designed such that they can be switched, so that they can be switched from circulating-air inlet operation to outside-air inlet operation or from circulating-air outlet operation to outside-air outlet operation.
Further features and embodiments of the invention will be apparent from the claims, the figures and the description of the figures. The features and combinations of features which are mentioned above and are described in the following text can be used not only in the respectively stated combination, but also in other combinations or on their own without departing from the scope of the invention.
Further designs of the invention are illustrated and explained in the drawing figures.